1. Field of the Invention
This invention relates in general to communications networks, and more particularly to a method and apparatus for providing information to network operators for determining cost accounting between the network operators.
2. Description of Related Art
The state of communications technology, particularly that which affects the Internet, is currently in flux and subject to rapid and often uncoordinated growth. The ubiquity and diversity of personal computers and set-top boxes has placed significant pressure on the providers of communications system infrastructure to accommodate the alarming increase in the number of new users that demand immediate access to Internet and other network resources. The rapid development of new and sophisticated software made available to users of such services places additional demands on system infrastructure.
Conducting commerce over the Internet and other networks is a practice that is gaining acceptance and popularity. By way of example, traditional on-line services, such as those offered by Internet providers, typical charge customers a monthly fee for access to basic services and resources, such as proprietary and public databases of information. Such traditional service providers also advertise any number of products or services which are purchasable on-line by the user.
Other forms of Internet commercialization currently being considered or implemented include offering of video and audio conferencing services, and a variety of other real-time and non-real-time services. The providers of these services, as well as the providers of communications system infrastructure, are currently facing a number of complex issues, including management of network capacity, load, and traffic to support real-time, non-real-time, and high-bandwidth services, and implementing a viable billing scheme that accounts for the use of such services.
The communications industry is expending considerable attention and investment on high speed solutions including gigabit networking. For example, one particular technology is referred to as asynchronous transfer mode (ATM). Those skilled in the art understand ATM to constitute a communications networking concept that can provide a capability to manage increases in network load, support both real-time and non-real-time applications, and offer, in certain circumstances, a guaranteed level of service quality.
A conventional ATM service architecture typically provides a number of predefined quality of service classes, often referred to as service categories. Each of the service categories includes a number of quality of service (QoS) parameters which define the nature of the respective service category. In other words, a specified service category provides performance to an ATM virtual connection (VCC or VPC) in a manner specified by a subset of the ATM performance parameters. The service categories defined in the ATM Forum specification reference herein below include, for example, a constant bit rate (CBR) category, a real-time variable bit rate (rt-VBR) category, a non-real-time variable bit rate (nrt-VBR) category, an unspecified bit rate (UBR) category, and an available bit rate (ABR) category.
The constant bit rate service class is intended to support real-time applications that require a fixed quantity of bandwidth during the existence of the connection. A particular quality of service is negotiated to provide the CBR service, where the QoS parameters include characterization of the peak cell rate (PCR), the cell loss rate (CLR), the cell transfer delay (CTD), and the cell delay variation (CDV). Conventional ATM traffic management schemes guarantee that the user-contracted QoS is maintained in order to support, for example, real-time applications, such as circuit emulation and voice/video applications, which require tightly constrained delay variations.
The non-real-time VBR service class is intended to support non-real-time applications, where the resulting network traffic can be characterized as having frequent data bursts. Similarly, the real-time variable bit rate service category may be used to support "bursty" network traffic conditions. The rt-VBR service category differs from the nrt-VBR service category in that the former is intended to support real-time applications, such as voice and video applications. Both the real-time and non-real-time VBR service categories are characterized in terms of a peak cell rate (PCR), a sustainable cell rate (SCR), and a maximum burst size (MBS).
The unspecified bit rate (UBR) service category is often regarded as a "best effort service," in that it does not specify traffic-related service guarantees. As such, the UBR service category is intended to support non-real-time applications, including traditional computer communications applications such as file transfers and e-mail.
The available bit rate (ABR) service category provides for the allocation of available bandwidth to users by controlling the rate of traffic through use of a feedback mechanism. The feedback mechanism permits cell transmission rates to be varied in an effort to control or avoid traffic congestion, and to more effectively utilize available bandwidth. A resource management (RM) cell precedes the transmission of data cells, which is transmitted from source to destination and back to the source, in order to provide traffic information to the source.
Although the current ATM service architecture described above would appear to provide, at least at a conceptual level, viable solutions to the many problems facing the communications industry, ATM, as currently defined, requires implementation of a complex traffic management scheme in order meet the objectives articulated in the various ATM specifications and recommendations currently being considered. In order to effectively manage traffic flow in a network, conventional ATM traffic management schemes must assess a prodigious number of traffic condition indicators, including service class parameters, traffic parameters, quality of service parameters and the like. A non-exhaustive listing of such parameters and other ATM traffic management considerations is provided in ITU-T Recommendation I.371, entitled Traffic Control and Congestion Control in B-ISDN, and in Traffic Management Specification, version 4.0 (af-tm-0056.000, April 1996), published by the Technical Committee of the ATM Forum.
Nevertheless, ATM is the current technology of choice when quality of service guarantees are critical. Still, Gigabit Ethernet is simpler, and a less expensive alternative in LAN environments where it is often more expedient to overbuild network capacity. Regardless of the technology, the increased bandwidth improved flow control is necessary in the developing high speed networks to prevent traffic loss.
Notwithstanding the complexity of conventional traffic management schemes, current specifications and recommendations fail to adequately address the need of service providers for a methodology that provides for accurate and reliable charging of services utilized by user's of the network.
In global Internet there are a huge number of network operators and service provides. As the packets in the network goes typically through several networks managed by different operators, some type of contracts are needed to regulate the traffic. Up to now, these contracts have typically been based on the principle that two adjacent operators transmit the traffic from the other operator's network free of charge, and the only restriction has been the link capacity between networks.
This arrangement works quite well as far as the network service is based on a best effort service without any resource reservation or usage based charging. But now the situation is changing dramatically due to the emerging resource reservation protocols, guaranteed services etc. There is a compelling need to control more thoroughly the traffic between operators, and specify what kind of compensation is needed. These contracts tend to be quite complicated as there are several service classes with different quality and traffic parameters. Thus, the control system of the contract will be complicated and hard to implement.
Up to now, there have not been any realistic, that is simple enough, proposals for controlling and charging the traffic between network operators in cases where guaranteed services with resource reservation are used. Current systems, if there is any realistic one, are complex and difficult to manage. For example, a charging scheme that accounts for most or all of the currently defined ATM traffic management properties would necessarily be complex and would typically require administration by highly skilled operators. The high overhead and maintenance costs to support such a billing scheme would likely be passed on to the network provider and, ultimately, to the network user.
Some commentators have suggested that a solution to these problems may be found by increasing the bandwidth or capacity of the network (e.g., the Internet). Implementing this overly simplistic solution would require an appreciable investment of hardware, software, and, most likely, replacing existing communication lines with high bandwidth transmission lines, such as fiber optic lines. This suggested solution, however, would likely result in undisciplined network expansion and uncoordinated management of network traffic. Also, such a solution, if implemented, would appear to obviate the need for much of the sophisticated traffic management features currently defined in ATM specifications.
It can be seen that there is a need for a device which can be used to control the traffic between network operators.
It can also be seen that there is a need for a system which can be used to fairly divide the costs and incomes between operators.